package cn.lt.domain.strategy.service.armory;

import cn.lt.domain.strategy.model.entity.StrategyAwardEntity;
import cn.lt.domain.strategy.model.entity.StrategyEntity;
import cn.lt.domain.strategy.model.entity.StrategyRuleEntity;
import cn.lt.domain.strategy.repository.IStrategyRepository;
import cn.lt.types.enums.ResponseCode;
import cn.lt.types.exception.AppException;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.security.SecureRandom;
import java.util.*;

/**
 * 策略装配库（兵工厂），负责初始化策略计算
 *
 * @author lt
 * @date 2025/04/30
 */
@Service
@Slf4j
public class StrategyArmoryDispatch implements IStrategyArmory, IStrategyDispatch {

    @Resource
    private IStrategyRepository repository;

    @Override
    public boolean assembleLotteryStrategy(Long strategyId) {
//1.        查询策略配置
        List<StrategyAwardEntity> strategyAwardEntities = repository.queryStrategyAwardList(strategyId);
        assembleLotteryStrategy(String.valueOf(strategyId), strategyAwardEntities);

//        2. 权重策略配置--适用于 rule_weight 权重规则配置
        StrategyEntity strategyEntity = repository.queryStrategyEntityByStratrgyId(strategyId);
        String ruleWeight = strategyEntity.getRuleWeight();
        if (null == ruleWeight) return true;

        StrategyRuleEntity strategyRuleEntity = repository.queryStraregyRule(strategyId, ruleWeight);
        if (null == strategyRuleEntity) {
            throw new AppException(ResponseCode.STRATEGY_RULE_WEIGHT_IS_NULL.getCode(), ResponseCode.STRATEGY_RULE_WEIGHT_IS_NULL.getInfo());
        }
        Map<String, List<Integer>> ruleWeightValueMap = strategyRuleEntity.getRuleWeightValue();

        Set<String> keys = ruleWeightValueMap.keySet();
        for (String key : keys) {
            List<Integer> ruleWeightValues = ruleWeightValueMap.get(key);
            ArrayList<StrategyAwardEntity> strategyAwardEntitiesClone = new ArrayList<>(strategyAwardEntities);
            strategyAwardEntitiesClone.removeIf(entity -> !ruleWeightValues.contains(entity.getAwardId()));
            assembleLotteryStrategy(String.valueOf(strategyId).concat("_").concat(key), strategyAwardEntitiesClone);

        }

        return true;
    }

    private void assembleLotteryStrategy(String key, List<StrategyAwardEntity> strategyAwardEntities) {

//      1. 获取最小概率值
        BigDecimal minAwardRate = strategyAwardEntities.stream()
                .map(StrategyAwardEntity::getAwardRate)
                .min(BigDecimal::compareTo)
                .orElse(BigDecimal.ZERO);

//        2. 获取概率值的综合
        BigDecimal totalAwardRate = strategyAwardEntities.stream()
                .map(StrategyAwardEntity::getAwardRate)
                .reduce(BigDecimal.ZERO, BigDecimal::add);
        System.out.println("totalAwardRate : " + totalAwardRate);

//        3. 用 1 % 0.0001 获取概率范围，百分位，千分位
        BigDecimal rateRange = totalAwardRate.divide(minAwardRate, 0, RoundingMode.CEILING);
//      4. 生成策略
        ArrayList<Integer> strategyAwardSearchRateTables = new ArrayList<>(rateRange.intValue());
        for (StrategyAwardEntity strategyAwardEntity : strategyAwardEntities) {
            Integer awardId = strategyAwardEntity.getAwardId();
            BigDecimal awardRate = strategyAwardEntity.getAwardRate();

//            计算出每个概率值需要存放到查找表的数量，循环填充
            for (int i = 0; i < rateRange.multiply(awardRate).setScale(0, RoundingMode.CEILING).intValue(); i++) {
                strategyAwardSearchRateTables.add(awardId);
            }
        }
//        5. 乱序
        Collections.shuffle(strategyAwardSearchRateTables);
//      6. 转换为集合
        HashMap<Integer, Integer> shuffleStrategyAwardSearchRateTables = new HashMap<>();
        for (int i = 0; i < strategyAwardSearchRateTables.size(); i++) {
            shuffleStrategyAwardSearchRateTables.put(i, strategyAwardSearchRateTables.get(i));
        }
//      7. 存储到 Redis
        repository.stroeStrategyAwardSearchRateTables(key, (long) shuffleStrategyAwardSearchRateTables.size(), shuffleStrategyAwardSearchRateTables);

    }

    @Override
    public Integer getRandomAwardId(Long strategyId) {
//        分布式部署下，不一定为当前应用做的策略装配。也就是值不一定会保存到本应用，而是分布式应用，所以需要从Redis中获取。
        int rateRange = repository.getRateRange(strategyId);
//          通过生成的随机值，获取概率值奖品查找表的结果
        return repository.getStrategyAwardAssemble(String.valueOf(strategyId), new SecureRandom().nextInt(rateRange));
    }

    @Override
    public Integer getRandomAwardId(Long strategyId, String ruleWeightValue) {

        String key = String.valueOf(strategyId).concat("_").concat(ruleWeightValue);
//        分布式部署下，不一定为当前应用做的策略装配。也就是值不一定会保存到本应用，而是分布式应用，所以需要从Redis中获取。
        int rateRange = repository.getRateRange(key);
//          通过生成的随机值，获取概率值奖品查找表的结果
        return repository.getStrategyAwardAssemble(key, new SecureRandom().nextInt(rateRange));

    }
}
